Terminal device, network device and methods therein

ABSTRACT

A method in a terminal device. The method includes determining a DeModulation Reference Signal (DMRS) configuration for a Physical Uplink Shared Channel (PUSCH) and transmitting to a network device the PUSCH using the DMRS configuration along with a preamble, in a random access message.

TECHNICAL FIELD

The present disclosure relates to wireless communication, and moreparticularly, to a terminal device, a network device and methodstherein.

BACKGROUND

Random access is performed by a terminal device, e.g., User Equipment(UE), in New Radio (NR) and Long Term Evolution (LTE) networks foraccessing a new cell. Once a random access procedure is completed, aterminal device can be connected to a network device, e.g., evolvedNodeB (eNB) or (next) generation NodeB (gNB), and communicate with thenetwork device using dedicated transmissions.

A four-step random access procedure has been defined for NR. FIG. 1Ashows a signaling sequence of a four-step random access procedure. Asshown, at 101, a UE detects a Synchronization Signal (SS) from a gNB. At102, the UE decodes Master Information Block (MIB) and SystemInformation Block (SIB) (i.e., Remaining Minimum System Information(RMSI) and Other System Information (OSI), which may be distributed overmultiple physical channels such as Physical Broadcast Channel (PBCH) andPhysical Downlink Shared Channel (PDSCH), to acquire random accesstransmission parameters. At 111, where the UE transmits a PhysicalRandom Access Channel (PRACH) preamble, or Message 1, to the gNB. ThegNB detects the Message 1 and responds with a Random Access Response(RAR), or Message 2, at 112. At 113, the UE transmits a Physical UplinkShared Channel (PUSCH), or Message 3, to the gNB in accordance withconfiguration information for PUSCH transmission carried in the RAR. At114, the gNB transmits a Contention Resolution Message, or Message 4, tothe UE.

In order to minimize the number of channel accesses, which is importantfor e.g. operations in unlicensed frequency bands where Listen BeforeTalk (LBT) is required before transmission, a two-step random accessprocedure has also been proposed for NR. Instead of using the four steps111-114, the two-step random access procedure completes random access inonly two steps, also referred to as Message A and Message B. FIG. 1Bshows a signaling sequence of a two-step random access procedure. Asshown, the steps 101-102 in FIG. 1B are the same as the steps 101-102 inFIG. 1A. At 121, the UE transmits a PRACH preamble and a PUSCH in onemessage (i.e., Message A) to the gNB. The PUSCH may include higher layerdata such as Radio Resource Control (RRC) connection request, possiblywith some small additional payload. At 122, the gNB transmits Message Bto the UE, including UE identifier assignment, timing advanceinformation and CRM, etc.

A DeModulation Reference Signal (DMRS) is transmitted with the PUSCH(Message 3 in FIG. 1A or Message A in FIG. 1B), for use by the gNB toestimate an uplink channel so as to demodulate the PUSCH.

SUMMARY

It is an object of the present disclosure to provide a terminal device,a network device and methods therein, capable of determining a DMRSconfiguration to be used for a PUSCH in a two-step random accessprocedure.

According to a first aspect of the present disclosure, a method in aterminal device is provided. The method includes: determining a DMRSconfiguration for a PUSCH; and transmitting to a network device thePUSCH using the DMRS configuration along with a preamble, in a randomaccess message.

In an embodiment, the operation of determining the DMRS configurationmay be based on one or more of: a frequency hopping configuration, aPUSCH mapping type, a PUSCH duration, a number of symbols for the DMRS,a maximum number of additional DMRS symbols, or a Code DivisionMultiplexing (CDM) group type.

In an embodiment, the DMRS configuration may include a time domainresource for DMRS. The operation of determining the DMRS configurationmay include determining the time domain resource for DMRS based on oneor more of: a frequency hopping configuration, a PUSCH mapping type, aPUSCH duration, a number of symbols for the DMRS, a maximum number ofadditional DMRS symbols, or a CDM group type.

In an embodiment, the one or more of the frequency hoppingconfiguration, the PUSCH mapping type, the PUSCH duration, the number ofsymbols for DMRS, the maximum number of additional DMRS symbols or theCDM group type may be predetermined by default or determined based on aresource and/or sequence for the preamble.

In an embodiment, the one or more of the frequency hoppingconfiguration, the PUSCH mapping type, the PUSCH duration, the number ofsymbols for DMRS, the maximum number of additional DMRS symbols or theCDM group type may be received from the network device via signaling.

In an embodiment, the signaling may include Radio Resource Control (RRC)signaling or Layer 1 signaling. The RRC signaling may include a systeminformation message and/or a dedicated signaling message, and the Layer1 signaling may include Downlink Control Information (DCI).

In an embodiment, the maximum number of additional DMRS symbols may bedetermined based on a moving speed of the terminal device.

In an embodiment, the time domain resource for DMRS may be determinedbased on a predetermined mapping between the time domain resource forDRMS and the one or more of the frequency hopping configuration, thePUSCH mapping type, the PUSCH duration, the number of symbols for DMRS,the maximum number of additional DMRS symbols or the CDM group type.

In an embodiment, the DMRS configuration may include a DMRS port and/ora DMRS sequence. The operation of determining the DMRS configuration mayinclude determining the DMRS port and/or the DMRS sequence based on aresource and/or sequence for the preamble and/or on a resource for thePUSCH.

In an embodiment, the operation of determining the DMRS port and/or theDMRS sequence may include: determining the DMRS port as a DMRS port thatis mapped to the resource and/or sequence for the preamble and/or to theresource for the PUSCH, and/or determining the DMRS sequence as a DMRSsequence that is mapped to the resource and/or sequence for the preambleand/or to the resource for the PUSCH. Alternatively, the operation ofdetermining the DMRS port and/or the DMRS sequence may include:selecting the DMRS port randomly from a set of DMRS ports that aremapped to the resource and/or sequence for the preamble and/or to theresource for the PUSCH, and/or selecting the DMRS sequence randomly froma set of DMRS sequences that are mapped to the resource and/or sequencefor the preamble and/or to the resource for the PUSCH.

In an embodiment, the operation of determining the DMRS sequence mayinclude: generating the DMRS sequence by using an identifier of thepreamble as an initialization parameter.

In an embodiment, the random access message may be a message in atwo-step random access procedure.

In an embodiment, the preamble may be selected from a set of preamblesreserved for two-step random access only, or the PUSCH may betransmitted over a time-frequency resource selected from a set oftime-frequency resources reserved for two-step random access only.

According to a second aspect of the present disclosure, a terminaldevice is provided. The terminal device includes: a determining unitconfigured to determine a DMRS configuration for a PUSCH; and atransmitting unit configured to transmit to a network device the PUSCHusing the DMRS configuration along with a preamble, in a random accessmessage.

The respective embodiments and features described above in connectionwith the first aspect also apply to the second aspect.

According to a third aspect of the present disclosure, a terminal deviceis provided. The terminal device includes a transceiver, a processor anda memory. The memory contains instructions executable by the processorwhereby the terminal device is operative to: determine a DMRSconfiguration for a PUSCH; and transmit to a network device the PUSCHusing the DMRS configuration along with a preamble, in a random accessmessage.

In an embodiment, the memory may further contain instructions executableby the processor whereby the terminal device is operative to perform themethod according to the above first aspect.

According to a fourth aspect of the present disclosure, a computerreadable storage medium is provided. The computer readable storagemedium has computer program instructions stored thereon. The computerprogram instructions, when executed by a processor in a terminal device,cause the terminal device to: determine a DMRS configuration for aPUSCH; and transmit to a network device the PUSCH using the DMRSconfiguration along with a preamble, in a random access message.

In an embodiment, the computer program instructions, when executed bythe processor in the terminal device, may further cause the terminaldevice to perform the method according to the above first aspect.

According to a fifth aspect of the present disclosure, a method in anetwork device is provided. The method includes: detecting a preamblefrom a terminal device, as a part of a random access message, the randomaccess message further including a PUSCH; and determining a DMRSconfiguration for the PUSCH.

In an embodiment, the operation of determining the DMRS configurationmay be based on one or more of: a frequency hopping configuration, aPUSCH mapping type, a PUSCH duration, a number of symbols for the DMRS,a maximum number of additional DMRS symbols, or a CDM group type.

In an embodiment, the DMRS configuration may include a time domainresource for DMRS. The operation of determining the DMRS configurationmay include determining the time domain resource for DMRS based on oneor more of: a frequency hopping configuration, a PUSCH mapping type, aPUSCH duration, a number of symbols for the DMRS, a maximum number ofadditional DMRS symbols, or a CDM group type.

In an embodiment, the one or more of the frequency hoppingconfiguration, the PUSCH mapping type, the PUSCH duration, the number ofsymbols for DMRS, the maximum number of additional DMRS symbols or theCDM group type may be predetermined by default or determined based on aresource and/or sequence for the preamble.

In an embodiment, the method may further include transmitting the one ormore of the frequency hopping configuration, the PUSCH mapping type, thePUSCH duration, the number of symbols for DMRS, the maximum number ofadditional DMRS symbols or the CDM group type to the terminal device viasignaling.

In an embodiment, the signaling may include RRC signaling or Layer 1signaling. The RRC signaling may include a system information messageand/or a dedicated signaling message, and the Layer 1 signaling mayinclude DCI.

In an embodiment, the maximum number of additional DMRS symbols may bedetermined based on a moving speed of the terminal device.

In an embodiment, the time domain resource for DMRS may be determinedbased on a predetermined mapping between the time domain resource forDRMS and the one or more of the frequency hopping configuration, thePUSCH mapping type, the PUSCH duration, the number of symbols for DMRS,the maximum number of additional DMRS symbols or the CDM group type.

In an embodiment, the DMRS configuration may include a DMRS port and/ora DMRS sequence. The operation of determining the DMRS configuration mayinclude determining the DMRS port and/or the DMRS sequence based on aresource and/or sequence for the preamble and/or on a resource for thePUSCH.

In an embodiment, the operation of determining the DMRS port and/or theDMRS sequence may include: determining the DMRS port as a DMRS port thatis mapped to the resource and/or sequence for the preamble and/or to theresource for the PUSCH, and/or determining the DMRS sequence as a DMRSsequence that is mapped to the resource and/or sequence for the preambleand/or to the resource for the PUSCH. Alternatively, the operation ofdetermining the DMRS port and/or the DMRS sequence may include:determining the DMRS port randomly from a set of DMRS ports that aremapped to the resource and/or sequence for the preamble and/or to theresource for the PUSCH, and/or determining the DMRS sequence randomlyfrom a set of DMRS sequences that are mapped to the resource and/orsequence for the preamble and/or to the resource for the PUSCH.

In an embodiment, the operation of determining the DMRS sequence mayinclude: generating the DMRS sequence by using an identifier of thepreamble as an initialization parameter.

In an embodiment, the random access message may be a message in atwo-step random access procedure. The operation of detecting thepreamble as a part of the random access message may include: determiningthat the preamble is selected from a set of preambles reserved fortwo-step random access only, or that the PUSCH is transmitted over atime-frequency resource selected from a set of time-frequency resourcesreserved for two-step random access only.

In an embodiment, the method may further include demodulating the PUSCHbased on the DMRS configuration.

According to a sixth aspect of the present disclosure, a network deviceis provided. The network device includes: a detecting unit configured todetect a preamble from a terminal device, as a part of a random accessmessage, the random access message further including a PUSCH; and adetermining unit configured to determine a DMRS configuration for thePUSCH.

The respective embodiments and features described above in connectionwith the fifth aspect also apply to the sixth aspect.

According to a seventh aspect of the present disclosure, a networkdevice is provided. The network device includes a transceiver, aprocessor and a memory. The memory contains instructions executable bythe processor whereby the network device is operative to: detect apreamble from a terminal device, as a part of a random access message,the random access message further including a PUSCH; and determine aDMRS configuration for the PUSCH.

In an embodiment, the memory may further contain instructions executableby the processor whereby the network device is operative to perform themethod according to the above fifth aspect.

According to an eighth aspect of the present disclosure, a computerreadable storage medium is provided. The computer readable storagemedium has computer program instructions stored thereon. The computerprogram instructions, when executed by a processor in a network device,cause the network device to: detect a preamble from a terminal device,as a part of a random access message, the random access message furtherincluding a PUSCH; and determine a DMRS configuration for the PUSCH.

In an embodiment, the computer program instructions, when executed by aprocessor in a network device, may further cause the network device toperform the method according to the above fifth aspect.

According to a ninth aspect of the present disclosure, a communicationsystem is provided. The communication system includes a host computerincluding: processing circuitry configured to provide user data; and acommunication interface configured to forward the user data to acellular network for transmission to a UE. The cellular network includesa base station having a radio interface and processing circuitry. Thebase station's processing circuitry is configured to perform the methodaccording to the fifth aspect.

In an embodiment, the communication system can further include the basestation.

In an embodiment, the communication system can further include the UE.The UE is configured to communicate with the base station.

In an embodiment, the processing circuitry of the host computer can beconfigured to execute a host application, thereby providing the userdata. The UE can include processing circuitry configured to execute aclient application associated with the host application.

According to a tenth aspect of the present disclosure, a method isprovided. The method is implemented in a communication system includinga host computer, a base station and a UE. The method includes: at thehost computer, providing user data; and at the host computer, initiatinga transmission carrying the user data to the UE via a cellular networkcomprising the base station. The base station can perform the methodaccording to the fifth aspect.

In an embodiment, the method further can include: at the base station,transmitting the user data.

In an embodiment, the user data can be provided at the host computer byexecuting a host application. The method can further include: at the UE,executing a client application associated with the host application.

According to an eleventh aspect of the present disclosure, acommunication system is provided. The communication system includes ahost computer including: processing circuitry configured to provide userdata; and a communication interface configured to forward user data to acellular network for transmission to a UE. The UE includes a radiointerface and processing circuitry. The UE's processing circuitry isconfigured to perform the method according to the first aspect.

In an embodiment, the communication system can further include the UE.

In an embodiment, the cellular network can further include a basestation configured to communicate with the UE.

In an embodiment, the processing circuitry of the host computer can beconfigured to execute a host application, thereby providing the userdata. The UE's processing circuitry can be configured to execute aclient application associated with the host application.

According to a twelfth aspect of the present disclosure, a method isprovided. The method is implemented in a communication system includinga host computer, a base station and a UE. The method includes: at thehost computer, providing user data; and at the host computer, initiatinga transmission carrying the user data to the UE via a cellular networkcomprising the base station. The UE can perform the method according tothe first aspect.

In an embodiment, the method can further include: at the UE, receivingthe user data from the base station.

According to a thirteenth aspect of the present disclosure, acommunication system is provided. The communication system includes ahost computer including: a communication interface configured to receiveuser data originating from a transmission from a UE to a base station.The UE includes a radio interface and processing circuitry. The UE'sprocessing circuitry is configured to: perform the method according tothe first aspect.

In an embodiment, the communication system can further include the UE.

In an embodiment, the communication system can further include the basestation. The base station can include a radio interface configured tocommunicate with the UE and a communication interface configured toforward to the host computer the user data carried by a transmissionfrom the UE to the base station.

In an embodiment, the processing circuitry of the host computer can beconfigured to execute a host application. The UE's processing circuitrycan be configured to execute a client application associated with thehost application, thereby providing the user data.

In an embodiment, the processing circuitry of the host computer can beconfigured to execute a host application, thereby providing requestdata. The UE's processing circuitry can be configured to execute aclient application associated with the host application, therebyproviding the user data in response to the request data.

According to a fourteenth aspect of the present disclosure, a method isprovided. The method is implemented in a communication system includinga host computer, a base station and a UE. The method includes: at thehost computer, receiving user data transmitted to the base station fromthe UE. The UE can perform the method according to the first aspect.

In an embodiment, the method can further include: at the UE, providingthe user data to the base station.

In an embodiment, the method can further include: at the UE, executing aclient application, thereby providing the user data to be transmitted;and at the host computer, executing a host application associated withthe client application.

In an embodiment, the method can further include: at the UE, executing aclient application; and at the UE, receiving input data to the clientapplication, the input data being provided at the host computer byexecuting a host application associated with the client application. Theuser data to be transmitted is provided by the client application inresponse to the input data.

According to a fifteenth aspect of the present disclosure, acommunication system is provided. The communication system includes ahost computer including a communication interface configured to receiveuser data originating from a transmission from a UE to a base station.The base station includes a radio interface and processing circuitry.The base station's processing circuitry is configured to perform themethod according to the fifth aspect.

In an embodiment, the communication system can further include the basestation.

In an embodiment, the communication system can further include the UE.The UE can be configured to communicate with the base station.

In an embodiment, the processing circuitry of the host computer can beconfigured to execute a host application; the UE can be configured toexecute a client application associated with the host application,thereby providing the user data to be received by the host computer.

According to a sixteenth aspect of the present disclosure, a method isprovided. The method is implemented in a communication system includinga host computer, a base station and a UE. The method includes: at thehost computer, receiving, from the base station, user data originatingfrom a transmission which the base station has received from the UE. Thebase station can perform the method according to the fifth aspect.

In an embodiment, the method can further include: at the base station,receiving the user data from the UE.

In an embodiment, the method can further include: at the base station,initiating a transmission of the received user data to the hostcomputer.

With the embodiments of the present disclosure, the DMRS configurationto be used for a PUSCH in a two-step random access procedure can bedetermined, such that a DMRS can be transmitted and/or receivedaccordingly and thus the PUSCH can be demodulated properly.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages will be moreapparent from the following description of embodiments with reference tothe figures, in which:

FIG. 1A is a sequence diagram showing a four-step random accessprocedure;

FIG. 1B is a sequence diagram showing a two-step random accessprocedure;

FIG. 2 is a flowchart illustrating a method in a terminal deviceaccording to an embodiment of the present disclosure;

FIG. 3 is a flowchart illustrating a method in a network deviceaccording to another embodiment of the present disclosure;

FIG. 4 is a block diagram of a terminal node according to an embodimentof the present disclosure;

FIG. 5 is a block diagram of a terminal node according to anotherembodiment of the present disclosure;

FIG. 6 is a block diagram of a network node according to anotherembodiment of the present disclosure;

FIG. 7 is a block diagram of a network node according to anotherembodiment of the present disclosure;

FIG. 8 schematically illustrates a telecommunication network connectedvia an intermediate network to a host computer;

FIG. 9 is a generalized block diagram of a host computer communicatingvia a base station with a user equipment over a partially wirelessconnection; and

FIGS. 10 to 13 are flowcharts illustrating methods implemented in acommunication system including a host computer, a base station and auser equipment.

DETAILED DESCRIPTION

As used herein, the term “wireless communication network” refers to anetwork following any suitable communication standards, such as NR,LTE-Advanced (LTE-A), LTE, Wideband Code Division Multiple Access(WCDMA), High-Speed Packet Access (HSPA), and so on. Furthermore, thecommunications between a terminal device and a network device in thewireless communication network may be performed according to anysuitable generation communication protocols, including, but not limitedto, Global System for Mobile Communications (GSM), Universal MobileTelecommunications System (UMTS), Long Term Evolution (LTE), and/orother suitable 1G (the first generation), 2G (the second generation),2.5G, 2.75G, 3G (the third generation), 4G (the fourth generation),4.5G, 5G (the fifth generation) communication protocols, wireless localarea network (WLAN) standards, such as the IEEE 802.11 standards; and/orany other appropriate wireless communication standard, such as theWorldwide Interoperability for Microwave Access (WiMax), Bluetooth,and/or ZigBee standards, and/or any other protocols either currentlyknown or to be developed in the future.

The term “network node” or “network device” refers to a device in awireless communication network via which a terminal device accesses thenetwork and receives services therefrom. The network node or networkdevice refers to a base station (BS), an access point (AP), or any othersuitable device in the wireless communication network. The BS may be,for example, a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB),or gNB, a Remote Radio Unit (RRU), a radio header (RH), a remote radiohead (RRH), a relay, a low power node such as a femto, a pico, and soforth. Yet further examples of the network device may includemulti-standard radio (MSR) radio equipment such as MSR BSs, networkcontrollers such as radio network controllers (RNCs) or base stationcontrollers (BSCs), base transceiver stations (BTSs), transmissionpoints, transmission nodes. More generally, however, the network devicemay represent any suitable device (or group of devices) capable,configured, arranged, and/or operable to enable and/or provide aterminal device access to the wireless communication network or toprovide some service to a terminal device that has accessed the wirelesscommunication network.

The term “terminal device” refers to any end device that can access awireless communication network and receive services therefrom. By way ofexample and not limitation, the terminal device refers to a mobileterminal, user equipment (UE), or other suitable devices. The UE may be,for example, a Subscriber Station (SS), a Portable Subscriber Station, aMobile Station (MS), or an Access Terminal (AT). The terminal device mayinclude, but not limited to, portable computers, desktop computers,image capture terminal devices such as digital cameras, gaming terminaldevices, music storage and playback appliances, a mobile phone, acellular phone, a smart phone, voice over IP (VoIP) phones, wirelesslocal loop phones, tablets, personal digital assistants (PDAs), wearableterminal devices, vehicle-mounted wireless terminal devices, wirelessendpoints, mobile stations, laptop-embedded equipment (LEE),laptop-mounted equipment (LME), USB dongles, smart devices, wirelesscustomer-premises equipment (CPE) and the like. In the followingdescription, the terms “terminal device”, “terminal”, “user equipment”and “UE” may be used interchangeably. As one example, a terminal devicemay represent a UE configured for communication in accordance with oneor more communication standards promulgated by the 3rd GenerationPartnership Project (3GPP), such as 3GPP's GSM, UMTS, LTE, and/or 5Gstandards. As used herein, a “user equipment” or “UE” may notnecessarily have a “user” in the sense of a human user who owns and/oroperates the relevant device. In some embodiments, a terminal device maybe configured to transmit and/or receive information without directhuman interaction. For instance, a terminal device may be designed totransmit information to a network on a predetermined schedule, whentriggered by an internal or external event, or in response to requestsfrom the wireless communication network. Instead, a UE may represent adevice that is intended for sale to, or operation by, a human user butthat may not initially be associated with a specific human user.

The terminal device may support device-to-device (D2D) communication,for example by implementing a 3GPP standard for sidelink communication,and may in this case be referred to as a D2D communication device.

As yet another example, in an Internet of Things (IOT) scenario, aterminal device may represent a machine or other device that performsmonitoring and/or measurements, and transmits the results of suchmonitoring and/or measurements to another terminal device and/or networkequipment. The terminal device may in this case be a machine-to-machine(M2M) device, which may in a 3GPP context be referred to as amachine-type communication (MTC) device. As one particular example, theterminal device may be a UE implementing the 3GPP narrow band internetof things (NB-IoT) standard. Particular examples of such machines ordevices are sensors, metering devices such as power meters, industrialmachinery, or home or personal appliances, for example refrigerators,televisions, personal wearables such as watches etc. In other scenarios,a terminal device may represent a vehicle or other equipment that iscapable of monitoring and/or reporting on its operational status orother functions associated with its operation.

As used herein, a downlink transmission refers to a transmission fromthe network device to a terminal device, and an uplink transmissionrefers to a transmission in an opposite direction.

References in the specification to “one embodiment,” “an embodiment,”“an example embodiment,” and the like indicate that the embodimentdescribed may include a particular feature, structure, orcharacteristic, but it is not necessary that every embodiment includesthe particular feature, structure, or characteristic. Moreover, suchphrases are not necessarily referring to the same embodiment. Further,when a particular feature, structure, or characteristic is described inconnection with an embodiment, it is submitted that it is within theknowledge of one skilled in the art to affect such feature, structure,or characteristic in connection with other embodiments whether or notexplicitly described.

It shall be understood that although the terms “first” and “second” etc.may be used herein to describe various elements, these elements shouldnot be limited by these terms. These terms are only used to distinguishone element from another. For example, a first element could be termed asecond element, and similarly, a second element could be termed a firstelement, without departing from the scope of example embodiments. Asused herein, the term “and/or” includes any and all combinations of oneor more of the associated listed terms. The terminology used herein isfor the purpose of describing particular embodiments only and is notintended to be liming of example embodiments. As used herein, thesingular forms “a”, “an” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. It willbe further understood that the terms “comprises”, “comprising”, “has”,“having”, “includes” and/or “including”, when used herein, specify thepresence of stated features, elements, and/or components etc., but donot preclude the presence or addition of one or more other features,elements, components and/ or combinations thereof.

In the following description and claims, unless defined otherwise, alltechnical and scientific terms used herein have the same meaning ascommonly understood by one of ordinary skills in the art to which thisdisclosure belongs.

In the four-step random access procedure as shown in FIG. 1A, the DMRSconfiguration, e.g., the time domain resource and frequency domainresource for DMRS transmission, is determined based on the configurationinformation carried in Message 2. However, in the two-step random accessprocedure as shown in FIG. 1B, there is no Message 2 before the UEtransmits the PUSCH (in Message A). In this case, it is desired todetermine the DMRS configuration to be used for the PUSCH in thetwo-step random access procedure.

In NR, there are various configurations for DMRS.

For example, a DMRS can be a single-symbol signal or a double-symbolsignal, and the latter is only used for dedicated PDSCH and PUSCHtransmissions.

Further, there can be two types of frequency mappings of DMRS, referredto as Type 1 (or Code Division Multiplexing (CDM) group Type 1) and Type2 (or CDM group Type 2), respectively. Type 1 is comb based, with 2 CDMgroups. Type 2 is not comb based, with 3 CDM groups.

The time mapping of DMRS to symbols within a slot can be depend on ascheduling/mapping type of PUSCH, which is dynamically indicated inDownlink Control Information (DCI) that schedules the PUSCH. For PUSCHmapping Type A, which is slot based, a DMRS may start at Symbol 3 or 4from a slot boundary, depending on a configuration indicated in PhysicalBroadcast Channel (PBCH). For PUSCH mapping Type B, which is anon-slot-based (or mini-slot based) scheduling, a DMRS may start inSymbol 1 of PUSCH. Also, one or more additional DMRS symbols could beconfigured within a PUSCH duration.

A number of DMRS ports can be configured. For example, up to 4 or 8 DMRSports can be multiplexed for Type 1 and up to 6 or 12 ports can bemultiplexed for Type 2, for single-symbol and double-symbol DMRSsrespectively. Frequency Division Multiplexing (FDM), FrequencyDivision-Orthogonal Coverage Code (FD-OCC) and/or TimeDivision-Orthogonal Coverage Code (TD-OCC) can be used to separateorthogonal DMRS ports.

Furthermore, a DMRS, or DMRS sequence, can be generated as specified inSections 6.4.1.1.1.1 and 6.4.1.1.1.2 of the 3^(rd) GenerationPartnership Project (3GPP) Technical Specification (TS) 38.211, V15.4.0,which is incorporated herein by reference in its entirety.

The DMRS configuration for Message 3 in the four-step random accessprocedure is also specified in TS 38.211. According to Section 2.1.3 ofTS 38.211, for a PUSCH carrying Message 3, N_(ID) ^(n) ^(SCID) =N_(ID)^(cell) (for OFDM (Orthogonal Frequency Division Multiplexing)) orn_(ID) ^(RS)=N_(ID) ^(cell) (for DFT-S-OFDM (Discrete FourierTransform-Spread OFDM)) is applied for DMRS sequence generation inSections 6.4.1.1.1.1 and 6.4.1.1.1.2, respectively. Type 1,single-symbol based DMRS is always used in the random access proceduresince these are the default DMRS configurations prior to dedicated RRCconfigurations.

Table 6.4.1.1.3-3 in TS 38.211, reproduced below as Table 1, definesPUSCH DMRS positions within a slot for single-symbol DMRS, withintra-slot frequency hopping disabled.

TABLE 1 DM-RS positions l PUSCH mapping type A PUSCH mapping type Bl_(d) in dmrs-AdditionalPosition dmrs-AdditionalPosition symbols 0 1 2 30 1 2 3 <4 — — — — l₀ l₀ l₀ l₀ 4 l₀ l₀ l₀ l₀ l₀ l₀ l₀ l₀ 5 l₀ l₀ l₀ l₀l₀ l₀, 4 l₀, 4 l₀, 4 6 l₀ l₀ l₀ l₀ l₀ l₀, 4 l₀, 4 l₀, 4 7 l₀ l₀ l₀ l₀ l₀l₀, 4 l₀, 4 l₀, 4 8 l₀ l₀, 7 l₀, 7 l₀, 7 l₀ l₀, 6 l₀, 3, 6 l₀, 3, 6 9 l₀l₀, 7 l₀, 7 l₀, 7 l₀ l₀, 6 l₀, 3, 6 l₀, 3, 6 10 l₀ l₀, 9 l₀, 6, 9 l₀, 6,9 l₀ l₀, 8 l₀, 4, 8 l₀, 3, 6, 9 11 l₀ l₀, 9 l₀, 6, 9 l₀, 6, 9 l₀ l₀, 8l₀, 4, 8 l₀, 3, 6, 9 12 l₀ l₀, 9 l₀, 6, 9 l₀, 5, 8, 11 l₀ l₀, 10 l₀, 5,10 l₀, 3, 6, 9 13 l₀ l₀, 11 l₀, 7, 11 l₀, 5, 8, 11 l₀ l₀, 10 l₀, 5, 10l₀, 3, 6, 9 14 l₀ l₀, 11 l₀, 7, 11 l₀, 5, 8, 11 l₀ l₀, 10 l₀, 5, 10 l₀,3, 6, 9

Table 6.4.1.1.3-4 in TS 38.211, reproduced below as Table 2, definesPUSCH DMRS positions within a slot for double-symbol DMRS, withintra-slot frequency hopping disabled.

TABLE 2 DM-RS positions l PUSCH mapping type A PUSCH mapping type Bl_(d) in dmrs-AdditionalPosition dmrs-AdditionalPosition symbols 0 1 2 30 1 2 3 <4 — — — — 4 l₀ l₀ — — 5 l₀ l₀ l₀ l₀ 6 l₀ l₀ l₀ l₀ 7 l₀ l₀ l₀ l₀8 l₀ l₀ l₀ l₀, 5 9 l₀ l₀ l₀ l₀, 5 10 l₀ l₀, 8 l₀ l₀, 7 11 l₀ l₀, 8 l₀l₀, 7 12 l₀ l₀, 8 l₀ l₀, 9 13 l₀ l₀, 10 l₀ l₀, 9 14 l₀ l₀, 10 l₀ l₀, 9

Table 6.4.1.1.3-6 in TS 38.211, reproduced below as Table 3, definesPUSCH DMRS positions within a slot for single-symbol DMRS, withintra-slot frequency hopping enabled.

TABLE 3 DM-RS positions l PUSCH mapping type A PUSCH mapping type B l₀ =2 l₀ = 3 l₀ = 0 dmrs-AdditionalPosition dmrs-AdditionalPositiondmrs-AdditonalPosition 0 1 0 1 0 1 l_(d) in 1^(st) 2^(nd) 1^(st) 2^(nd)1^(st) 2^(nd) 1^(st) 2^(nd) 1^(st) 2^(nd) 1^(st) 2^(nd) symbols hop hophop hop hop hop hop hop hop hop hop hop <3 — — — — — — — — 0 0 0 0 4 2 02 0 3 0 3 0 0 0 0 0 5, 6 2 0 2 0, 4 3 0 3 0, 4 0 0 0, 4 0, 4 7 2 0 2, 60, 4 3 0 3 0, 4 0 0 0, 4 0, 4

For details of Tables 1-3, reference can be made to Section 6.4.1.1.3 inTS 38.211 and description thereof will be omitted here.

For PUSCH mapping Type A, one front loaded DMRS symbol plus twoadditional DMRS symbols can be the default DMRS configuration for therandom access procedure. For PUSCH mapping Type B with frequency hoppingdisabled, Type B, up to two additional DMRS symbols(dmrs-AdditionalPosition=2) can be the default configuration for therandom access procedure.

A list of applicable PUSCH durations scheduled by a RAR is given inSection 6.1.2.1.1 in 3GPP TS 38.214, V15.4.0, which is incorporatedherein by reference in its entirety. In particular, Table 6.1.2.1.1-2 inTS 38.214, reproduced below as Table 4, gives a default PUSCH timedomain resource allocation A for normal Cyclic Prefix (CP), and Table6.1.2.1.1-3 in TS 38.214, reproduced below as Table 5, gives a defaultPUSCH time domain resource allocation A for extended CP.

TABLE 4 PUSCH Row index mapping type K₂ S L 1 Type A j 0 14 2 Type A j 012 3 Type A j 0 10 4 Type B j 2 10 5 Type B j 4 10 6 Type B j 4 8 7 TypeB j 4 6 8 Type A j + 1 0 14 9 Type A j + 1 0 12 10 Type A j + 1 0 10 11Type A j + 2 0 14 12 Type A j + 2 0 12 13 Type A j + 2 0 10 14 Type B j8 6 15 Type A j + 3 0 14 16 Type A j + 3 0 10

TABLE 5 PUSCH Row index mapping type K₂ S L 1 Type A j 0 8 2 Type A j 012 3 Type A j 0 10 4 Type B j 2 10 5 Type B j 4 4 6 Type B j 4 8 7 TypeB j 4 6 8 Type A j + 1 0 8 9 Type A j + 1 0 12 10 Type A j + 1 0 10 11Type A j + 2 0 6 12 Type A j + 2 0 12 13 Type A j + 2 0 10 14 Type B j 84 15 Type A j + 3 0 8 16 Type A j + 3 0 10

FIG. 2 is a flowchart illustrating a method 200 according to anembodiment of the present disclosure. The method 200 can be performed ina terminal device, e.g., a UE.

At block 210, a DMRS configuration for a PUSCH is determined.

In an example, the DMRS configuration may be determined based on one ormore of the following configuration parameters:

-   -   a frequency hopping configuration (i.e., enabled or disabled),    -   a PUSCH mapping type (i.e., Type A or Type B),    -   a PUSCH duration (i.e., the number of OFDM symbols for PUSCH),    -   a number of symbols for the DMRS (i.e., single-symbol or        double-symbol),    -   a maximum number of additional DMRS symbols (i.e.,        dmrs-AdditionalPosition), or    -   a CDM group type (Type 1 or Type 2).

In an example, the DMRS configuration may include a time domain resourcefor DMRS. In the block 210, the time domain resource for DMRS can bedetermined based on one or more of the following configurationparameters:

-   -   a frequency hopping configuration (i.e., enabled or disabled),    -   a PUSCH mapping type (i.e., Type A or Type B),    -   a PUSCH duration (i.e., the number of OFDM symbols for PUSCH),    -   a number of symbols for the DMRS (i.e., single-symbol or        double-symbol),    -   a maximum number of additional DMRS symbols (i.e.,        dmrs-AdditionalPosition), or    -   a CDM group type (Type 1 or Type 2).

For example, one or more of these configuration parameters can bepredetermined by default. As an example, by default, the frequencyhopping can be disabled, the PUSCH mapping type can be Type A, the PUSCHduration can be a fixed value, the number of symbols for DMRS can beone, the maximum number of additional DMRS symbols can be a fixed value(e.g., dmrs-AdditionalPosition=2), and the CDM group type can be Type 1.

Alternatively, one or more of these configuration parameters can bedetermined based on a resource and/or sequence for the preamble. Forexample, there can be a predetermined mapping between the configurationparameters and the resource and/or sequence for the preamble, and theconfiguration parameters can be determined based on the predeterminedmapping.

Alternatively, one or more of these configuration parameters can bereceived from the network device via signaling. For example, thesignaling may include RRC signaling or Layer 1 signaling. The RRCsignaling may include a system information message and/or a dedicatedsignaling message, and the Layer 1 signaling may include DCI.

In an example, the maximum number of additional DMRS symbols can bedetermined based on a moving speed of the terminal device. For example,when the moving speed of the terminal device is lower than a threshold(e.g., 120 km), dmrs-AdditionalPosition=1; or otherwisedmrs-AdditionalPosition=2.

In an example, the time domain resource for DMRS can be determined basedon a predetermined mapping between the time domain resource for DRMS andone or more of the above configuration parameters. For example, Tables1-5 as described above can be reused. The time domain resource for DMRScan be determined by looking up these tables based on the configurationparameters.

Further, the DMRS configuration may include a DMRS port and/or a DMRSsequence. In the block 210, the DMRS port and/or the DMRS sequence canbe determined based on a resource and/or sequence for the preambleand/or on a resource for the PUSCH.

For example, one DMRS port (and/or one DMRS sequence) can be mapped tothe resource and/or sequence for the preamble and/or to the resource forthe PUSCH. The DMRS port can be determined as a DMRS port that is mappedto the resource and/or sequence for the preamble and/or to the resourcefor the PUSCH. The DMRS sequence can be determined as a DMRS sequencethat is mapped to the resource and/or sequence for the preamble and/orto the resource for the PUSCH. Alternatively, a set of DMRS ports(and/or DMRS sequences) can be mapped to the resource and/or sequencefor the preamble and/or to the resource for the PUSCH. The DMRS port canbe selected randomly from the set of DMRS ports that are mapped to theresource and/or sequence for the preamble and/or to the resource for thePUSCH. The DMRS sequence can be selected randomly from the set of DMRSsequences that are mapped to the resource and/or sequence for thepreamble and/or to the resource for the PUSCH. Such random selection ofthe DMRS port and/or the DMRS sequence reduces the probability ofcollision between DMRSs from different terminal devices.

In an example, the DMRS sequence can be generated by using an identifierof the preamble as an initialization parameter. In this way, theprobability of collision between DMRSs from different terminal devicescan be reduced. For example, in the DMRS sequence generation asspecified in Section 6.4.1.1.1.1 of TS 38.211, the pseudo-randomsequence generator may be initialized with

c=(2¹⁷(N _(symb) ^(slot) n _(s,f) ^(μ) +l+1)(2N _(ID) ^(n) ^(SCID)+1)°2N _(ID) ^(n) ^(SCID) +n _(SCID)+PreambleID)mod 2³¹,

where PreamblelD denotes the identifier of the preamble. Alternatively,in the DMRS sequence generation as specified in Section 6.4.1.1.1.2 ofTS 38.211, f_(gh) can be a function of a cell identifier and theidentifier of the preamble. For example, f_(fg) or the sequence number vcan be given by:

f _(gh)=(f _(gh)+preambleID)mod 30, or v=(v+preamblelD)mod 30,

where PreamblelD denotes the identifier of the preamble.

At block 220, the PUSCH using the DMRS configuration is transmitted,along with a preamble, in a random access message to a network device(e.g., a gNB).

Here, the random access message can be a message in a two-step randomaccess procedure, e.g., Message A in FIG. 1B.

In an example, the preamble can be selected from a set of preamblesreserved for two-step random access only, or the PUSCH can betransmitted over a time-frequency resource selected from a set oftime-frequency resources reserved for two-step random access only. Thisallows the network device to determine that the preamble is a part of aMessage A in a two-step random access and then attempt to detect thePUSCH in the Message A.

FIG. 3 is a flowchart illustrating a method 300 according to anembodiment of the present disclosure. The method 300 can be performed ina network device, e.g., a gNB.

At block 310, a preamble from a terminal device (e.g., a UE) isdetermined, as a part of a random access message. The random accessmessage further includes a PUSCH. Here, the random access message can bea message in a two-step random access procedure, e.g., Message A in FIG.1B.

In an example, in the block 310, it can be determined that the preambleis selected from a set of preambles reserved for two-step random accessonly, or that the PUSCH is transmitted over a time-frequency resourceselected from a set of time-frequency resources reserved for two-steprandom access only.

At block 320, a DMRS configuration for the PUSCH is determined.

In an example, the DMRS configuration may be determined based on one ormore of the following configuration parameters:

-   -   a frequency hopping configuration (i.e., enabled or disabled),    -   a PUSCH mapping type (i.e., Type A or Type B),    -   a PUSCH duration (i.e., the number of OFDM symbols for PUSCH),    -   a number of symbols for the DMRS (i.e., single-symbol or        double-symbol),    -   a maximum number of additional DMRS symbols (i.e.,        dmrs-AdditionalPosition), or    -   a CDM group type (Type 1 or Type 2).

In particular, in an example, the DMRS configuration may include a timedomain resource for DMRS. In the block 320, the time domain resource forDMRS can be determined based on one or more of the followingconfiguration parameters:

-   -   a frequency hopping configuration (i.e., enabled or disabled),    -   a PUSCH mapping type (i.e., Type A or Type B),    -   a PUSCH duration (i.e., the number of OFDM symbols for PUSCH),    -   a number of symbols for the DMRS (i.e., single-symbol or        double-symbol),    -   a maximum number of additional DMRS symbols (i.e.,        dmrs-AdditionalPosition), or    -   a CDM group type (Type 1 or Type 2).

For example, one or more of these configuration parameters can bepredetermined by default or can be determined based on a resource and/orsequence for the preamble.

In an example, one or more of these configuration parameters can betransmitted to the terminal device via signaling. For example, thesignaling may include RRC signaling or Layer 1 signaling. The RRCsignaling may include a system information message and/or a dedicatedsignaling message, and the Layer 1 signaling may include DCI.

In an example, the maximum number of additional DMRS symbols can bedetermined based on a moving speed of the terminal device.

In an example, the time domain resource for DMRS can be determined basedon a predetermined mapping between the time domain resource for DRMS andone or more of the above configuration parameters. For example, Tables1-5 as described above can be reused. The time domain resource for DMRScan be determined by looking up these tables based on the configurationparameters.

Further, the DMRS configuration may include a DMRS port and/or a DMRSsequence. In the block 320, the DMRS port and/or the DMRS sequence canbe determined based on a resource and/or sequence for the preambleand/or on a resource for the PUSCH. For example, the DMRS port can bedetermined as a DMRS port that is mapped to the resource and/or sequencefor the preamble and/or to the resource for the PUSCH, and/or the DMRSsequence can be determined as a DMRS sequence that is mapped to theresource and/or sequence for the preamble and/or to the resource for thePUSCH. Alternatively, the DMRS port can be selected randomly from a setof DMRS ports that are mapped to the resource and/or sequence for thepreamble and/or to the resource for the PUSCH, and/or the DMRS sequencecan be selected randomly from a set of DMRS sequences that are mapped tothe resource and/or sequence for the preamble and/or to the resource forthe PUSCH.

In an example, the DMRS sequence can be generated by using an identifierof the preamble as an initialization parameter.

The operation in the block 320 corresponds to the operation in the block210 performed at the terminal device. Thus, for further details of theoperation in the block 320, reference can be made to the block 210 asdescribed above.

In an example, the method 300 can further include a step of demodulatingthe PUSCH based on the DMRS configuration. In particular, the networkdevice can detect the DMRS based on the DMRS configuration, estimate anuplink channel based on the DMRS and then demodulate the PUSCH based onthe estimated channel.

Correspondingly to the method 200 as described above, a terminal deviceis provided. FIG. 4 is a block diagram of a terminal device 400according to an embodiment of the present disclosure.

As shown in FIG. 4, the terminal device 400 includes a determining unit410 configured to determine a DMRS configuration for a PUSCH. Theterminal device 400 further includes a transmitting unit 420 configuredto transmit to a network device the PUSCH using the DMRS configurationalong with a preamble, in a random access message.

In an embodiment, the determining unit 410 can be configured todetermine the time domain resource for DMRS based on one or more of: afrequency hopping configuration, a PUSCH mapping type, a PUSCH duration,a number of symbols for the DMRS, a maximum number of additional DMRSsymbols, or a CDM group type.

In an embodiment, the DMRS configuration may include a time domainresource for DMRS. The determining unit 410 can be configured todetermine the time domain resource for DMRS based on one or more of: afrequency hopping configuration, a PUSCH mapping type, a PUSCH duration,a number of symbols for the DMRS, a maximum number of additional DMRSsymbols, or a CDM group type.

In an embodiment, the one or more of the frequency hoppingconfiguration, the PUSCH mapping type, the PUSCH duration, the number ofsymbols for DMRS, the maximum number of additional DMRS symbols or theCDM group type may be predetermined by default or determined based on aresource and/or sequence for the preamble.

In an embodiment, the one or more of the frequency hoppingconfiguration, the PUSCH mapping type, the PUSCH duration, the number ofsymbols for DMRS, the maximum number of additional DMRS symbols or theCDM group type may be received from the network device via signaling.

In an embodiment, the signaling may include RRC signaling or Layer 1signaling. The RRC signaling may include a system information messageand/or a dedicated signaling message, and the Layer 1 signaling mayinclude DCI.

In an embodiment, the maximum number of additional DMRS symbols may bedetermined based on a moving speed of the terminal device.

In an embodiment, the time domain resource for DMRS may be determinedbased on a predetermined mapping between the time domain resource forDRMS and the one or more of the frequency hopping configuration, thePUSCH mapping type, the PUSCH duration, the number of symbols for DMRS,the maximum number of additional DMRS symbols or the CDM group type.

In an embodiment, the DMRS configuration may include a DMRS port and/ora DMRS sequence. The determining unit 410 can be configured to determinethe DMRS port and/or the DMRS sequence based on a resource and/orsequence for the preamble and/or on a resource for the PUSCH.

In an embodiment, the determining unit 410 can be configured todetermine the DMRS port as a DMRS port that is mapped to the resourceand/or sequence for the preamble and/or to the resource for the PUSCH,and/or determine the DMRS sequence as a DMRS sequence that is mapped tothe resource and/or sequence for the preamble and/or to the resource forthe PUSCH. Alternatively, the determining unit 410 can be configured toselect the DMRS port randomly from a set of DMRS ports that are mappedto the resource and/or sequence for the preamble and/or to the resourcefor the PUSCH, and/or select the DMRS sequence randomly from a set ofDMRS sequences that are mapped to the resource and/or sequence for thepreamble and/or to the resource for the PUSCH.

In an embodiment, the determining unit 410 can be configured to generatethe DMRS sequence by using an identifier of the preamble as aninitialization parameter.

In an embodiment, the random access message may be a message in atwo-step random access procedure.

In an embodiment, the preamble may be selected from a set of preamblesreserved for two-step random access only, or the PUSCH may betransmitted over a time-frequency resource selected from a set oftime-frequency resources reserved for two-step random access only.

The units 410 and 420 can be implemented as a pure hardware solution oras a combination of software and hardware, e.g., by one or more of: aprocessor or a micro-processor and adequate software and memory forstoring of the software, a Programmable Logic Device (PLD) or otherelectronic component(s) or processing circuitry configured to performthe actions described above, and illustrated, e.g., in FIG. 2.

FIG. 5 is a block diagram of a terminal device 500 according to anotherembodiment of the present disclosure.

The terminal device 500 includes a transceiver 510, a processor 520 anda memory 530. The memory 530 contains instructions executable by theprocessor 520 whereby the terminal device 500 is operative to performthe actions, e.g., of the procedure described earlier in conjunctionwith FIG. 2. Particularly, the memory 530 contains instructionsexecutable by the processor 520 whereby the terminal device 500 isoperative to: determine a DMRS configuration for a PUSCH; and transmitto a network device the PUSCH using the DMRS configuration along with apreamble, in a random access message.

In an embodiment, the operation of determining the DMRS configurationmay be based on one or more of: a frequency hopping configuration, aPUSCH mapping type, a PUSCH duration, a number of symbols for the DMRS,a maximum number of additional DMRS symbols, or a CDM group type.

In an embodiment, the DMRS configuration may include a time domainresource for DMRS. The operation of determining the DMRS configurationmay include determining the time domain resource for DMRS based on oneor more of: a frequency hopping configuration, a PUSCH mapping type, aPUSCH duration, a number of symbols for the DMRS, a maximum number ofadditional DMRS symbols, or a Code Division Multiplexing (CDM) grouptype.

In an embodiment, the one or more of the frequency hoppingconfiguration, the PUSCH mapping type, the PUSCH duration, the number ofsymbols for DMRS, the maximum number of additional DMRS symbols or theCDM group type may be predetermined by default or determined based on aresource and/or sequence for the preamble.

In an embodiment, the one or more of the frequency hoppingconfiguration, the PUSCH mapping type, the PUSCH duration, the number ofsymbols for DMRS, the maximum number of additional DMRS symbols or theCDM group type may be received from the network device via signaling.

In an embodiment, the signaling may include Radio Resource Control (RRC)signaling or Layer 1 signaling. The RRC signaling may include a systeminformation message and/or a dedicated signaling message, and the Layer1 signaling may include Downlink Control Information (DCI).

In an embodiment, the maximum number of additional DMRS symbols may bedetermined based on a moving speed of the terminal device.

In an embodiment, the time domain resource for DMRS may be determinedbased on a predetermined mapping between the time domain resource forDRMS and the one or more of the frequency hopping configuration, thePUSCH mapping type, the PUSCH duration, the number of symbols for DMRS,the maximum number of additional DMRS symbols or the CDM group type.

In an embodiment, the DMRS configuration may include a DMRS port and/ora DMRS sequence. The operation of determining the DMRS configuration mayinclude determining the DMRS port and/or the DMRS sequence based on aresource and/or sequence for the preamble and/or on a resource for thePUSCH.

In an embodiment, the operation of determining the DMRS port and/or theDMRS sequence may include: determining the DMRS port as a DMRS port thatis mapped to the resource and/or sequence for the preamble and/or to theresource for the PUSCH, and/or determining the DMRS sequence as a DMRSsequence that is mapped to the resource and/or sequence for the preambleand/or to the resource for the PUSCH. Alternatively, the operation ofdetermining the DMRS port and/or the DMRS sequence may include:selecting the DMRS port randomly from a set of DMRS ports that aremapped to the resource and/or sequence for the preamble and/or to theresource for the PUSCH, and/or selecting the DMRS sequence randomly froma set of DMRS sequences that are mapped to the resource and/or sequencefor the preamble and/or to the resource for the PUSCH.

In an embodiment, the operation of determining the DMRS sequence mayinclude: generating the DMRS sequence by using an identifier of thepreamble as an initialization parameter.

In an embodiment, the random access message may be a message in atwo-step random access procedure.

In an embodiment, the preamble may be selected from a set of preamblesreserved for two-step random access only, or the PUSCH may betransmitted over a time-frequency resource selected from a set oftime-frequency resources reserved for two-step random access only.

Correspondingly to the method 300 as described above, a network deviceis provided. FIG. 6 is a block diagram of a network device 600 accordingto an embodiment of the present disclosure.

As shown in FIG. 6, the network device 600 includes a detecting unit 610configured to detect a preamble from a terminal device, as a part of arandom access message the random access message further including aPUSCH. The network device 600 further includes a determining unit 620configured to determine a DMRS configuration for the PUSCH.

In an embodiment, the determining unit 620 can be configured todetermine the time domain resource for DMRS based on one or more of: afrequency hopping configuration, a PUSCH mapping type, a PUSCH duration,a number of symbols for the DMRS, a maximum number of additional DMRSsymbols, or a CDM group type.

In an embodiment, the DMRS configuration may include a time domainresource for DMRS. The determining unit 620 can be configured todetermine the time domain resource for DMRS based on one or more of: afrequency hopping configuration, a PUSCH mapping type, a PUSCH duration,a number of symbols for the DMRS, a maximum number of additional DMRSsymbols, or a CDM group type.

In an embodiment, the one or more of the frequency hoppingconfiguration, the PUSCH mapping type, the PUSCH duration, the number ofsymbols for DMRS, the maximum number of additional DMRS symbols or theCDM group type may be predetermined by default or determined based on aresource and/or sequence for the preamble.

In an embodiment, the network device 600 may further include atransmitting unit configured to transmit the one or more of thefrequency hopping configuration, the PUSCH mapping type, the PUSCHduration, the number of symbols for DMRS, the maximum number ofadditional DMRS symbols or the CDM group type to the terminal device viasignaling.

In an embodiment, the signaling may include RRC signaling or Layer 1signaling. The RRC signaling may include a system information messageand/or a dedicated signaling message, and the Layer 1 signaling mayinclude DCI.

In an embodiment, the maximum number of additional DMRS symbols may bedetermined based on a moving speed of the terminal device.

In an embodiment, the time domain resource for DMRS may be determinedbased on a predetermined mapping between the time domain resource forDRMS and the one or more of the frequency hopping configuration, thePUSCH mapping type, the PUSCH duration, the number of symbols for DMRS,the maximum number of additional DMRS symbols or the CDM group type.

In an embodiment, the DMRS configuration may include a DMRS port and/ora DMRS sequence. The determining unit 620 can be configured to determinethe DMRS port and/or the DMRS sequence based on a resource and/orsequence for the preamble and/or on a resource for the PUSCH.

In an embodiment, the determining unit 620 can be configured todetermine the DMRS port as a DMRS port that is mapped to the resourceand/or sequence for the preamble and/or to the resource for the PUSCH,and/or determine the DMRS sequence as a DMRS sequence that is mapped tothe resource and/or sequence for the preamble and/or to the resource forthe PUSCH. Alternatively, the determining unit 620 can be configured todetermine the DMRS port randomly from a set of DMRS ports that aremapped to the resource and/or sequence for the preamble and/or to theresource for the PUSCH, and/or determine the DMRS sequence randomly froma set of DMRS sequences that are mapped to the resource and/or sequencefor the preamble and/or to the resource for the PUSCH.

In an embodiment, the determining unit 620 can be configured to generatethe DMRS sequence by using an identifier of the preamble as aninitialization parameter.

In an embodiment, the random access message may be a message in atwo-step random access procedure. The detecting unit 610 can beconfigured to determine that the preamble is selected from a set ofpreambles reserved for two-step random access only, or that the PUSCH istransmitted over a time-frequency resource selected from a set oftime-frequency resources reserved for two-step random access only.

In an embodiment, the network device 600 may further include ademodulating unit configured to demodulate the PUSCH based on the DMRSconfiguration.

The units 610 and 620 can be implemented as a pure hardware solution oras a combination of software and hardware, e.g., by one or more of: aprocessor or a micro-processor and adequate software and memory forstoring of the software, a Programmable Logic Device (PLD) or otherelectronic component(s) or processing circuitry configured to performthe actions described above, and illustrated, e.g., in FIG. 3.

FIG. 7 is a block diagram of a network device 700 according to anotherembodiment of the present disclosure.

The network device 700 includes a transceiver 710, a processor 720 and amemory 730. The memory 730 contains instructions executable by theprocessor 720 whereby the network device 700 is operative to perform theactions, e.g., of the procedure described earlier in conjunction withFIG. 3. Particularly, the memory 730 contains instructions executable bythe processor 720 whereby the network device 700 is operative to detecta preamble from a terminal device, as a part of a random access message,the random access message further including a PUSCH; and determine aDMRS configuration for the PUSCH.

In an embodiment, the operation of determining the DMRS configurationmay be based on one or more of: a frequency hopping configuration, aPUSCH mapping type, a PUSCH duration, a number of symbols for the DMRS,a maximum number of additional DMRS symbols, or a CDM group type.

In an embodiment, the DMRS configuration may include a time domainresource for DMRS. The operation of determining the DMRS configurationmay include determining the time domain resource for DMRS based on oneor more of: a frequency hopping configuration, a PUSCH mapping type, aPUSCH duration, a number of symbols for the DMRS, a maximum number ofadditional DMRS symbols, or a CDM group type.

In an embodiment, the one or more of the frequency hoppingconfiguration, the PUSCH mapping type, the PUSCH duration, the number ofsymbols for DMRS, the maximum number of additional DMRS symbols or theCDM group type may be predetermined by default or determined based on aresource and/or sequence for the preamble.

In an embodiment, the memory 730 may further contain instructionsexecutable by the processor 720 whereby the network device 700 isoperative to transmit the one or more of the frequency hoppingconfiguration, the PUSCH mapping type, the PUSCH duration, the number ofsymbols for DMRS, the maximum number of additional DMRS symbols or theCDM group type to the terminal device via signaling.

In an embodiment, the signaling may include RRC signaling or Layer 1signaling. The RRC signaling may include a system information messageand/or a dedicated signaling message, and the Layer 1 signaling mayinclude DCI.

In an embodiment, the maximum number of additional DMRS symbols may bedetermined based on a moving speed of the terminal device.

In an embodiment, the time domain resource for DMRS may be determinedbased on a predetermined mapping between the time domain resource forDRMS and the one or more of the frequency hopping configuration, thePUSCH mapping type, the PUSCH duration, the number of symbols for DMRS,the maximum number of additional DMRS symbols or the CDM group type.

In an embodiment, the DMRS configuration may include a DMRS port and/ora DMRS sequence. The operation of determining the DMRS configuration mayinclude determining the DMRS port and/or the DMRS sequence based on aresource and/or sequence for the preamble and/or on a resource for thePUSCH.

In an embodiment, the operation of determining the DMRS port and/or theDMRS sequence may include: determining the DMRS port as a DMRS port thatis mapped to the resource and/or sequence for the preamble and/or to theresource for the PUSCH, and/or determining the DMRS sequence as a DMRSsequence that is mapped to the resource and/or sequence for the preambleand/or to the resource for the PUSCH. Alternatively, the operation ofdetermining the DMRS port and/or the DMRS sequence may include:determining the DMRS port randomly from a set of DMRS ports that aremapped to the resource and/or sequence for the preamble and/or to theresource for the PUSCH, and/or determining the DMRS sequence randomlyfrom a set of DMRS sequences that are mapped to the resource and/orsequence for the preamble and/or to the resource for the PUSCH.

In an embodiment, the operation of determining the DMRS sequence mayinclude: generating the DMRS sequence by using an identifier of thepreamble as an initialization parameter.

In an embodiment, the random access message may be a message in atwo-step random access procedure. The operation of detecting thepreamble as a part of the random access message may include: determiningthat the preamble is selected from a set of preambles reserved fortwo-step random access only, or that the PUSCH is transmitted over atime-frequency resource selected from a set of time-frequency resourcesreserved for two-step random access only.

In an embodiment, the memory 730 may further contain instructionsexecutable by the processor 720 whereby the network device 700 isoperative to demodulate the PUSCH based on the DMRS configuration.

The present disclosure also provides at least one computer programproduct in the form of a non-volatile or volatile memory, e.g., anon-transitory computer readable storage medium, an ElectricallyErasable Programmable Read-Only Memory (EEPROM), a flash memory and ahard drive. The computer program product includes a computer program.The computer program includes: code/computer readable instructions,which when executed by the processor 520 causes the terminal device 500to perform the actions, e.g., of the procedure described earlier inconjunction with FIG. 2; or code/computer readable instructions, whichwhen executed by the processor 720 causes the network device 700 toperform the actions, e.g., of the procedure described earlier inconjunction with FIG. 3.

The computer program product may be configured as a computer programcode structured in computer program modules. The computer programmodules could essentially perform the actions of the flow illustrated inFIG. 2 or 3.

The processor may be a single CPU (Central Processing Unit), but couldalso comprise two or more processing units. For example, the processormay include general purpose microprocessors; instruction set processorsand/or related chips sets and/or special purpose microprocessors such asApplication Specific Integrated Circuits (ASICs). The processor may alsocomprise board memory for caching purposes. The computer program may becarried by a computer program product connected to the processor. Thecomputer program product may comprise a non-transitory computer readablestorage medium on which the computer program is stored. For example, thecomputer program product may be a flash memory, a Random Access Memory(RAM), a Read-Only Memory (ROM), or an EEPROM, and the computer programmodules described above could in alternative embodiments be distributedon different computer program products in the form of memories.

With reference to FIG. 8, in accordance with an embodiment, acommunication system includes a telecommunication network 810, such as a3GPP-type cellular network, which comprises an access network 811, suchas a radio access network, and a core network 814. The access network811 comprises a plurality of base stations 812 a, 812 b, 812 c, such asNBs, eNBs, gNBs or other types of wireless access points, each defininga corresponding coverage area 813 a, 813 b, 813 c. Each base station 812a, 812 b, 812 c is connectable to the core network 814 over a wired orwireless connection 815. A first UE 891 located in a coverage area 813 cis configured to wirelessly connect to, or be paged by, thecorresponding base station 812 c. A second UE 892 in a coverage area 813a is wirelessly connectable to the corresponding base station 812 a.While a plurality of UEs 891, 892 are illustrated in this example, thedisclosed embodiments are equally applicable to a situation where a soleUE is in the coverage area or where a sole UE is connecting to thecorresponding base station 812.

The telecommunication network 810 is itself connected to a host computer830, which may be embodied in the hardware and/or software of astandalone server, a cloud-implemented server, a distributed server oras processing resources in a server farm. The host computer 830 may beunder the ownership or control of a service provider, or may be operatedby the service provider or on behalf of the service provider.Connections 821 and 822 between the telecommunication network 810 andthe host computer 830 may extend directly from the core network 814 tothe host computer 830 or may go via an optional intermediate network820. An intermediate network 820 may be one of, or a combination of morethan one of, a public, private or hosted network; the intermediatenetwork 820, if any, may be a backbone network or the Internet; inparticular, the intermediate network 820 may comprise two or moresub-networks (not shown).

The communication system of FIG. 8 as a whole enables connectivitybetween the connected UEs 891, 892 and the host computer 830. Theconnectivity may be described as an over-the-top (OTT) connection 850.The host computer 830 and the connected UEs 891, 892 are configured tocommunicate data and/or signaling via the OTT connection 850, using theaccess network 811, the core network 814, any intermediate network 820and possible further infrastructure (not shown) as intermediaries. TheOTT connection 850 may be transparent in the sense that theparticipating communication devices through which the OTT connection 850passes are unaware of routing of uplink and downlink communications. Forexample, the base station 812 may not or need not be informed about thepast routing of an incoming downlink communication with data originatingfrom the host computer 830 to be forwarded (e.g., handed over) to aconnected UE 891. Similarly, the base station 812 need not be aware ofthe future routing of an outgoing uplink communication originating fromthe UE 891 towards the host computer 830.

Example implementations, in accordance with an embodiment, of the UE,base station and host computer discussed in the preceding paragraphswill now be described with reference to FIG. 9. In a communicationsystem 900, a host computer 910 comprises hardware 915 including acommunication interface 916 configured to set up and maintain a wired orwireless connection with an interface of a different communicationdevice of the communication system 900. The host computer 910 furthercomprises a processing circuitry 918, which may have storage and/orprocessing capabilities. In particular, the processing circuitry 918 maycomprise one or more programmable processors, application-specificintegrated circuits, field programmable gate arrays or combinations ofthese (not shown) adapted to execute instructions. The host computer 910further comprises software 911, which is stored in or accessible by thehost computer 910 and executable by the processing circuitry 918. Thesoftware 911 includes a host application 912. The host application 912may be operable to provide a service to a remote user, such as UE 930connecting via an OTT connection 950 terminating at the UE 930 and thehost computer 910. In providing the service to the remote user, the hostapplication 912 may provide user data which is transmitted using the OTTconnection 950.

The communication system 900 further includes a base station 920provided in a telecommunication system and comprising hardware 925enabling it to communicate with the host computer 910 and with the UE930. The hardware 925 may include a communication interface 926 forsetting up and maintaining a wired or wireless connection with aninterface of a different communication device of the communicationsystem 900, as well as a radio interface 927 for setting up andmaintaining at least a wireless connection 970 with the UE 930 locatedin a coverage area (not shown in FIG. 9) served by the base station 920.The communication interface 926 may be configured to facilitate aconnection 960 to the host computer 910. The connection 960 may bedirect or it may pass through a core network (not shown in FIG. 9) ofthe telecommunication system and/or through one or more intermediatenetworks outside the telecommunication system. In the embodiment shown,the hardware 925 of the base station 920 further includes a processingcircuitry 928, which may comprise one or more programmable processors,application-specific integrated circuits, field programmable gate arraysor combinations of these (not shown) adapted to execute instructions.The base station 920 further has software 921 stored internally oraccessible via an external connection.

The communication system 900 further includes the UE 930 alreadyreferred to. Its hardware 935 may include a radio interface 937configured to set up and maintain a wireless connection 970 with a basestation serving a coverage area in which the UE 930 is currentlylocated. The hardware 935 of the UE 930 further includes a processingcircuitry 938, which may comprise one or more programmable processors,application-specific integrated circuits, field programmable gate arraysor combinations of these (not shown) adapted to execute instructions.The UE 930 further comprises software 931, which is stored in oraccessible by the UE 930 and executable by the processing circuitry 938.The software 931 includes a client application 932. The clientapplication 932 may be operable to provide a service to a human ornon-human user via the UE 930, with the support of the host computer910. In the host computer 910, an executing host application 912 maycommunicate with the executing client application 932 via the OTTconnection 950 terminating at the UE 930 and the host computer 910. Inproviding the service to the user, the client application 932 mayreceive request data from the host application 912 and provide user datain response to the request data. The OTT connection 950 may transferboth the request data and the user data. The client application 932 mayinteract with the user to generate the user data that it provides.

It is noted that the host computer 910, the base station 920 and the UE930 illustrated in FIG. 9 may be similar or identical to the hostcomputer 830, one of base stations 812 a, 812 b, 812 c and one of UEs891, 892 of FIG. 8, respectively. This is to say, the inner workings ofthese entities may be as shown in FIG. 9 and independently, thesurrounding network topology may be that of FIG. 8.

In FIG. 9, the OTT connection 950 has been drawn abstractly toillustrate the communication between the host computer 910 and the UE930 via the base station 920, without explicit reference to anyintermediary devices and the precise routing of messages via thesedevices. Network infrastructure may determine the routing, which it maybe configured to hide from the UE 930 or from the service provideroperating the host computer 910, or both. While the OTT connection 950is active, the network infrastructure may further take decisions bywhich it dynamically changes the routing (e.g., on the basis of loadbalancing consideration or reconfiguration of the network).

Wireless connection 970 between the UE 930 and the base station 920 isin accordance with the teachings of the embodiments described throughoutthis disclosure. One or more of the various embodiments improve theperformance of OTT services provided to the UE 930 using the OTTconnection 950, in which the wireless connection 970 forms the lastsegment. More precisely, the teachings of these embodiments may improvethe radio resource utilization and thereby provide benefits such asreduced user waiting time.

A measurement procedure may be provided for the purpose of monitoringdata rate, latency and other factors on which the one or moreembodiments improve. There may further be an optional networkfunctionality for reconfiguring the OTT connection 950 between the hostcomputer 910 and the UE 930, in response to variations in themeasurement results. The measurement procedure and/or the networkfunctionality for reconfiguring the OTT connection 950 may beimplemented in software 911 and hardware 915 of the host computer 910 orin software 931 and hardware 935 of the UE 930, or both. In embodiments,sensors (not shown) may be deployed in or in association withcommunication devices through which the OTT connection 950 passes; thesensors may participate in the measurement procedure by supplying valuesof the monitored quantities exemplified above, or supplying values ofother physical quantities from which the software 911, 931 may computeor estimate the monitored quantities. The reconfiguring of the OTTconnection 950 may include message format, retransmission settings,preferred routing etc.; the reconfiguring need not affect the basestation 920, and it may be unknown or imperceptible to the base station920. Such procedures and functionalities may be known and practiced inthe art.

In certain embodiments, measurements may involve proprietary UEsignaling facilitating the host computer 910's measurements ofthroughput, propagation times, latency and the like. The measurementsmay be implemented in that the software 911 and 931 causes messages tobe transmitted, in particular empty or ‘dummy’ messages, using the OTTconnection 950 while it monitors propagation times, errors etc.

FIG. 10 is a flowchart illustrating a method implemented in acommunication system, in accordance with an embodiment. Thecommunication system includes a host computer, a base station and a UEwhich may be those described with reference to FIG. 8 and FIG. 9. Forsimplicity of the present disclosure, only drawing references to FIG. 10will be included in this section. In step 1010, the host computerprovides user data. In substep 1011 (which may be optional) of step1010, the host computer provides the user data by executing a hostapplication. In step 1020, the host computer initiates a transmissioncarrying the user data to the UE. In step 1030 (which may be optional),the base station transmits to the UE the user data which was carried inthe transmission that the host computer initiated, in accordance withthe teachings of the embodiments described throughout this disclosure.In step 1040 (which may also be optional), the UE executes a clientapplication associated with the host application executed by the hostcomputer.

FIG. 11 is a flowchart illustrating a method implemented in acommunication system, in accordance with an embodiment. Thecommunication system includes a host computer, a base station and a UEwhich may be those described with reference to FIG. 8 and FIG. 9. Forsimplicity of the present disclosure, only drawing references to FIG. 11will be included in this section. In step 1110 of the method, the hostcomputer provides user data. In an optional substep (not shown) the hostcomputer provides the user data by executing a host application. In step1120, the host computer initiates a transmission carrying the user datato the UE. The transmission may pass via the base station, in accordancewith the teachings of the embodiments described throughout thisdisclosure. In step 1130 (which may be optional), the UE receives theuser data carried in the transmission.

FIG. 12 is a flowchart illustrating a method implemented in acommunication system, in accordance with an embodiment. Thecommunication system includes a host computer, a base station and a UEwhich may be those described with reference to FIG. 8 and FIG. 9. Forsimplicity of the present disclosure, only drawing references to FIG. 12will be included in this section. In step 1210 (which may be optional),the UE receives input data provided by the host computer. Additionallyor alternatively, in step 1220, the UE provides user data. In substep1221 (which may be optional) of step 1220, the UE provides the user databy executing a client application. In substep 1211 (which may beoptional) of step 1210, the UE executes a client application whichprovides the user data in reaction to the received input data providedby the host computer. In providing the user data, the executed clientapplication may further consider user input received from the user.Regardless of the specific manner in which the user data was provided,the UE initiates, in substep 1230 (which may be optional), transmissionof the user data to the host computer. In step 1240 of the method, thehost computer receives the user data transmitted from the UE, inaccordance with the teachings of the embodiments described throughoutthis disclosure.

FIG. 13 is a flowchart illustrating a method implemented in acommunication system, in accordance with an embodiment. Thecommunication system includes a host computer, a base station and a UEwhich may be those described with reference to FIG. 8 and FIG. 9. Forsimplicity of the present disclosure, only drawing references to FIG. 13will be included in this section. In step 1310 (which may be optional),in accordance with the teachings of the embodiments described throughoutthis disclosure, the base station receives user data from the UE. Instep 1320 (which may be optional), the base station initiatestransmission of the received user data to the host computer. In step1330 (which may be optional), the host computer receives the user datacarried in the transmission initiated by the base station.

The disclosure has been described above with reference to embodimentsthereof. It should be understood that various modifications,alternations and additions can be made by those skilled in the artwithout departing from the spirits and scope of the disclosure.Therefore, the scope of the disclosure is not limited to the aboveparticular embodiments but only defined by the claims as attached.

1. A method in a terminal device, comprising: determining a DeModulationReference Signal (DMRS) configuration for a Physical Uplink SharedChannel (PUSCH); and transmitting to a network device the PUSCH usingthe DMRS configuration along with a preamble, in a random accessmessage, wherein the random access message is a message A in a two-steprandom access procedure.
 2. The method of claim 1, wherein saiddetermining the DMRS configuration is based on one or more of: afrequency hopping configuration, a PUSCH mapping type, a PUSCH duration,a number of symbols for the DMRS, a maximum number of additional DMRSsymbols, or a Code Division Multiplexing (CDM) group type.
 3. The methodof claim 1, wherein the DMRS configuration comprises a time domainresource for DMRS, and said determining the DMRS configuration comprisesdetermining the time domain resource for the DMRS based on one or moreof: a frequency hopping configuration, a PUSCH mapping type, a PUSCHduration, a number of symbols for the DMRS, a maximum number ofadditional DMRS symbols, or a Code Division Multiplexing (CDM) grouptype.
 4. The method of claim 2, wherein the one or more of the frequencyhopping configuration, the PUSCH mapping type, the PUSCH duration, thenumber of symbols for the DMRS, the maximum number of additional DMRSsymbols or the CDM group type are predetermined by default or determinedbased on a resource a sequence, or both the resource and the sequencefor the preamble.
 5. The method of claim 2, wherein the one or more ofthe frequency hopping configuration, the PUSCH mapping type, the PUSCHduration, the number of symbols for the DMRS, the maximum number ofadditional DMRS symbols or the CDM group type are received from thenetwork device via signaling.
 6. The method of claim 5, wherein thesignaling comprises Radio Resource Control (RRC) signaling or Layer 1signaling, the RRC signaling comprising a system information message, adedicated signaling message, or both the system information message andthe dedicated signaling message, and the Layer 1 signaling comprisingDownlink Control Information (DCI).
 7. The method of claim 2, whereinthe maximum number of additional DMRS symbols is determined based on amoving speed of the terminal device.
 8. The method of claim 3, whereinthe time domain resource for the DMRS is determined based on apredetermined mapping between the time domain resource for the DMRS andthe one or more of the frequency hopping configuration, the PUSCHmapping type, the PUSCH duration, the number of symbols for the DMRS,the maximum number of additional DMRS symbols or the CDM group type. 9.The method of claim 1, wherein the DMRS configuration comprises a DMRSport, a DMRS sequence, or both the DMRS port and the DMRS sequence, andsaid determining the DMRS configuration comprises determining the DMRSport, the DMRS sequence, or both the DMRS port and the DMRS sequence,based on a resource, a sequence, or both the resource and the sequence,for the preamble, to a resource for the PUSCH, or both for the preambleand to the resource for the PUSCH.
 10. The method of claim 9, whereinsaid determining the DMRS port, the DMRS sequence, or both the DMRS portand the DMRS sequence, comprises: determining the DMRS port as a DMRSport that is mapped to the resource, the sequence, or both the resourceand the sequence, for the preamble, to the resource for the PUSCH, orboth for the preamble and to the resource for the PUSCH, and/ordetermining the DMRS sequence as a DMRS sequence that is mapped to theresource, the sequence, or both the resource and the sequence, for thepreamble, to the resource for the PUSCH, or both for the preamble and tothe resource for the PUSCH, or selecting the DMRS port randomly from aset of DMRS ports that are mapped to the resource, the sequence, or boththe resource and the sequence for the preamble, to the resource for thePUSCH, or both for the preamble and to the resource for the PUSCH,and/or selecting the DMRS sequence randomly from a set of DMRS sequencesthat are mapped to the resource, the sequence, or both the resource andthe sequence, for the preamble, to the resource for the PUSCH, or bothfor the preamble and to the resource for the PUSCH.
 11. The method ofclaim 9, wherein said determining the DMRS sequence comprises generatingthe DMRS sequence by using an identifier of the preamble as aninitialization parameter.
 12. The method of claim 11, wherein thepreamble is selected from a set of preambles reserved for two-steprandom access only, or the PUSCH is transmitted over a time-frequencyresource selected from a set of time-frequency resources reserved fortwo-step random access only.
 13. A terminal device, comprising: aprocessor; and a memory, the memory comprising instructions which, whenexecuted by the processor, cause the terminal device is operative to:determine a DeModulation Reference Signal (DMRS) configuration for aPhysical Uplink Shared Channel (PUSCH); and transmit to a network devicethe PUSCH using the DMRS configuration along with a preamble, in arandom access message, wherein the random access message is a message Ain a two-step random access procedure. 14-16. (canceled)
 17. A method ina network device, comprising: detecting a preamble from a terminaldevice, as a part of a random access message, the random access messagefurther comprising a Physical Uplink Shared Channel (PUSCH) wherein therandom access message is a message A in a two-step random accessprocedure; and determining a DeModulation Reference Signal (DMRS)configuration for the PUSCH.
 18. The method of claim 17, wherein saiddetermining the DMRS configuration is based on one or more of: afrequency hopping configuration, a PUSCH mapping type, a PUSCH duration,a number of symbols for the DMRS, a maximum number of additional DMRSsymbols, or a Code Division Multiplexing (CDM) group type.
 19. Themethod of claim 17, wherein the DMRS configuration comprises a timedomain resource for DMRS, and said determining the DMRS configurationcomprises determining the time domain resource for DMRS based on one ormore of: a frequency hopping configuration, a PUSCH mapping type, aPUSCH duration, a number of symbols for the DMRS, a maximum number ofadditional DMRS symbols, or a Code Division Multiplexing (CDM) grouptype.
 20. The method of claim 18, wherein the one or more of thefrequency hopping configuration, the PUSCH mapping type, the PUSCHduration, the number of symbols for the DMRS, the maximum number ofadditional DMRS symbols or the CDM group type are predetermined bydefault or determined based on a resource a sequence, or both theresource and the sequence for the preamble.
 21. The method of claim 18,further comprising: transmitting the one or more of the frequencyhopping configuration, the PUSCH mapping type, the PUSCH duration, thenumber of symbols for the DMRS, the maximum number of additional DMRSsymbols or the CDM group type to the terminal device via signaling. 22.The method of claim 21, wherein the signaling comprises Radio ResourceControl (RRC) signaling or Layer 1 signaling, the RRC signalingcomprising a system information message, a dedicated signaling message,or both the system information message and the dedicated signalingmessage, and the Layer 1 signaling comprising Downlink ControlInformation (DCI).
 23. (canceled)
 24. The method of claim 19, whereinthe time domain resource for the DMRS is determined based on apredetermined mapping between the time domain resource for the DRMS andthe one or more of the frequency hopping configuration, the PUSCHmapping type, the PUSCH duration, the number of symbols for the DMRS,the maximum number of additional DMRS symbols or the CDM group type. 25.The method of claim 17, wherein the DMRS configuration comprises a DMRSport, a DMRS sequence, or both the DMRS port and the DMRS sequence, andsaid determining the DMRS configuration comprises determining the DMRSport, the DMRS sequence, or both the DMRS port and the DMRS sequence,based on a resource, a sequence, or both the resource and the sequencefor the preamble, to a resource for the PUSCH, or both for the preambleand to the resource for the PUSCH. 26-29. (canceled)
 30. A networkdevice, comprising: a processor; and a memory, the memory (730)comprising instructions which, when executed by the processor, cause thenetwork device to: detect a preamble from a terminal device, as a partof a random access message, the random access message further comprisinga Physical Uplink Shared Channel (PUSCH) wherein the random accessmessage is a message A in a two-step random access procedure; anddetermine a DeModulation Reference Signal (DMRS) configuration for thePUSCH. 31-33. (canceled)